[(('Oxides of Nitrogen', 'Nitrogen Oxide'), 0.90452879813369069),
(('Benzene', 'p-Xylene'), 0.88581555124515599),
(('Toluene', 'Benzene'), 0.87151084726988715),
(('Carbon Monoxide', 'p-Xylene'), 0.86564080864225246),
(('Oxides of Nitrogen', 'Nitrogen Dioxide'), 0.83675086477153748),
(('Toluene', 'p-Xylene'), 0.83197261683487078),
(('Toluene', 'Nitrogen Dioxide'), 0.80867372100149626),
(('Nitrogen Dioxide', 'p-Xylene'), 0.77020483803518547),
(('Nitrogen Dioxide', 'Benzene'), 0.72647322313726459),
(('Toluene', 'Carbon Monoxide'), 0.70428005317794384),
(('Toluene', 'Wind Direction'), 0.69426570373177565),
(('Wind Direction', 'Benzene'), 0.69210896732171157),
(('Carbon Monoxide', 'Benzene'), 0.68704861106395065),
(('Nitrogen Dioxide', 'Carbon Monoxide'), 0.67344908320223007),
(('Ambient Temperature', 'Wind Direction'), 0.67283787446242471),
(('Ambient Temperature', 'Ozone'), 0.67005151403895857),
(('Particulate Matter < 10 µg', 'p-Xylene'), 0.66511593611930897),
(('Wind Direction', 'p-Xylene'), 0.66173572393756486),
(('Particulate Matter < 10 µg', 'Benzene'), 0.65193187350344517),
(('Wind Direction', 'Carbon Monoxide'), 0.635984884439877),
(('Oxides of Nitrogen', 'p-Xylene'), 0.61457771756341162),
(('Ozone', 'Solar Radiation'), 0.61216242764548967),
(('Nitrogen Oxide', 'Nitrogen Dioxide'), 0.58197923614229519),
(('Toluene', 'Oxides of Nitrogen'), 0.5394747632349246),
(('Oxides of Nitrogen', 'Carbon Monoxide'), 0.53827747206642418),
(('Toluene', 'Particulate Matter < 10 µg'), 0.53701680429002474),
(('Toluene', 'Ambient Temperature'), 0.51861149863853473),
(('Ambient Temperature', 'Ammonia'), 0.51127951576150088)]